Kuroki Y, Shiozawa S, Sugimoto T, Kanatani M, Kaji H, Miyachi A, Chihara K
Department of Medicine, Kobe University School of Medicine, Japan.
Clin Exp Immunol. 1994 Mar;95(3):536-9. doi: 10.1111/j.1365-2249.1994.tb07032.x.
The effect of culture supernatants of c-fos-transfected MC3T3-E1 osteoblastic cells on osteoclastic bone resorption was studied. Human c-fos cDNA was integrated in the expression vector pH8, and the cells were transfected using the calcium phosphate precipitation technique. Osteoclastic bone resorption was quantified by the pit formation assay, and the osteoclast maturation from precursor was assessed by the generation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNC). The culture supernatants of MC3T3-E1 transfectants constitutively expressing c-fos gene enhanced osteoclast-like MNC formation from haematopoietic blast cells compared with those of control transfectants (P < 0.01). The culture supernatants also promoted osteoclastic bone resorption: the pit number, 118.7 +/- 38.5, was significantly higher than 19.0 +/- 10.1 of the control (P < 0.05). The absorption area, 12,394 +/- 3145 mm2, was significantly larger than 1646 +/- 314 mm2 of the control (P < 0.05). The culture supernatants also promoted bone resorption by purified chick osteoclasts (P < 0.05). The results show that constitutive expression of c-fos gene in osteoblastic MC3T3-E1 cells stimulates osteoclast maturation and osteoclastic bone resorption by releasing humoral mediator(s).
研究了c-fos转染的MC3T3-E1成骨细胞培养上清液对破骨细胞骨吸收的影响。将人c-fos cDNA整合到表达载体pH8中，采用磷酸钙沉淀技术转染细胞。通过蚀坑形成试验对破骨细胞骨吸收进行定量，通过抗酒石酸酸性磷酸酶（TRAP）阳性多核细胞（MNC）的生成评估破骨细胞从前体细胞的成熟情况。与对照转染细胞相比，组成性表达c-fos基因的MC3T3-E1转染细胞的培养上清液增强了造血母细胞中破骨细胞样MNC的形成（P<0.01）。培养上清液还促进了破骨细胞的骨吸收：蚀坑数量为118.7±38.5，显著高于对照的19.0±10.1（P<0.05）。吸收面积为12394±3145mm2，显著大于对照的1646±314mm2（P<0.05）。培养上清液还促进了纯化的鸡破骨细胞的骨吸收（P<0.05）。结果表明，成骨细胞MC3T3-E1细胞中c-fos基因的组成性表达通过释放体液介质刺激破骨细胞成熟和破骨细胞骨吸收。
